Dynamic control of uplink carrier aggregation in a wireless communication system based on UE operational circumstances

ABSTRACT

A method and system for controlling wireless service of a user equipment device (UE) by an access node. The access node serves the UE with uplink carrier-aggregation over a connection encompassing multiple uplink channels including a primary uplink channel (uplink PCell) and a secondary uplink channel (uplink SCell). Further, the access node dynamically sets a channel-quality threshold applicable to control when to deconfigure the uplink SCell from service of the UE, with the dynamically setting of the channel-quality threshold including setting the channel-quality threshold to a value selected based on one or more operational circumstances of the UE, such as whether the UE is engaged in uplink heavy or rather uplink light communication. And the access node applies the dynamically set channel-quality threshold to control when to deconfigure the uplink SCell from service of the UE.

BACKGROUND

A wireless communication system typically includes a number of accessnodes that are configured to provide wireless coverage areas in whichuser equipment devices (UEs) such as cell phones, tablet computers,tracking devices, embedded wireless modules, and other wirelesslyequipped communication devices (whether or not user operated), canoperate. Further, each access node could be coupled with a core networkthat provides connectivity with one or more transport networks, such asthe public switched telephone network (PSTN) and/or the Internet forinstance. With this arrangement, a UE within coverage of the systemcould engage in air interface communication with an access node andcould thereby communicate via the access node with various remotenetwork entities or with other UEs served by the access node.

Such a system could operate in accordance with a particular radio accesstechnology, with air-interface communications from the access nodes toUEs defining a downlink or forward link and air-interface communicationsfrom the UEs to the access nodes defining an uplink or reverse link.

Over the years, the industry has developed various generations of radioaccess technologies, in a continuous effort to increase available datarate and quality of service for end users. These generations have rangedfrom “1G,” which used simple analog frequency modulation to facilitatebasic voice-call service, to “4G”—such as Long Term Evolution (LTE),which facilitates mobile broadband service using technologies such asorthogonal frequency division multiplexing (OFDM) and multiple inputmultiple output (MIMO). And most recently, the industry is now exploringdevelopments in “5G” and particularly “5G NR” (5G New Radio), which mayuse a scalable OFDM air interface, advanced channel coding,massive-MIMO, beamforming, and/or other features, to support higher datarates and countless applications, such as mission-critical services,enhanced mobile broadband, and massive Internet of Things (IoT).

In accordance with the radio access technology, each access node couldbe configured to provide service on one or more carrier frequencies or“carriers.” Each carrier could be frequency division duplex (FDD),defining separate frequency channels for downlink and uplinkcommunication, or time division duplex (TDD), defining a singlefrequency channel multiplexed over time between downlink and uplink use.Further, each frequency channel of a carrier could occupy a particularfrequency bandwidth defining a range of frequency at a particularposition (e.g., defined by a center frequency or low-end and high-endfrequencies) in radio-frequency spectrum.

On the downlink and uplink, each carrier could be structured to definevarious physical resources and channels for carrying information betweenthe access nodes and UEs.

In an example configuration for instance, the air interface could bedivided over time into frames, subframes, and symbol time segments, andthe carrier bandwidth could be divided over frequency into subcarriers,so that the air interface would define an array of resource elementseach occupying one subcarrier and one symbol time segment. With thisexample configuration, the resource elements could be grouped withineach subframe to define physical resource blocks (PRBs) in which thesubcarriers can be modulated to carry data.

Further, certain resource elements or PRBs could be reserved for use tocarry particular types of data, such as control signaling and/oruser-plane communications.

For instance, in each downlink subframe, the resource elements in thefirst symbol time segments could be generally reserved to define acontrol region for carrying control signaling such as PRB-schedulingdirectives from the access node to UEs, and the resource elements in theremaining symbol time segments could be generally reserved to define adownlink shared traffic channel in which PRBs could be used to carrydata from the access node to UEs. Further, other resource elements couldbe reserved for other purposes. For instance, resource elementsdistributed throughout each downlink subframe could be reserved to carrya reference signal from the access node that UEs could measure as abasis to gauge coverage strength.

And in each uplink subframe, certain PRBs at the low-frequency end ofthe carrier bandwidth and at the high-frequency end of the carrierbandwidth could be generally reserved to define a control region forcarrying control signaling such as uplink scheduling requests from UEsto the access node, and other PRBs could be generally reserved to definean uplink shared channel in which PRBs could be used to carry data fromUEs to the access node.

OVERVIEW

When a UE enters into coverage of an access node under in an examplesystem, the UE could discover threshold strong coverage on one of theaccess node's carriers, and the UE could then responsively engage insignaling to connect with the access node on that carrier, such as toestablish a Radio Resource Control (RRC) connection. Further, acore-network controller could then coordinate setup or transfer of oneor more user-plane bearers defining virtual packet tunnels for carryinguser-plane data communications between the UE and a core-network gatewaysystem that provides connectivity with a transport network such as theInternet. Each such bearer could include a data-radio bearer (DRB)tunnel that extends over the air between the UE and then access node andan access-bearer that extends within the core network between the accessnode and the gateway system.

Once the UE is so connected and has one or more established bearers, theaccess node could then serve the UE on the carrier, scheduling use ofthe carrier's PRBs as needed to carry communications to or from the UE.

For instance, when packet-data arrives at the access node fortransmission to the UE, the access node could schedule use of certaindownlink PRBs in subframe to carry a transport-block of that data to theUE, the access node could transmit to the UE in the control region ofthat subframe a scheduling directive (e.g., a Downlink ControlInformation (DCI) message) that specifies the PRBs that will carry thedata, and the access node could transmit the data to the UE in thosePRBs. And when the UE has packet-data to transmit to the access node,the UE could transmit to the access node a scheduling request includinga buffer status report (BSR) indicating the quantity of data to betransmitted, the access node could schedule use of certain uplink PRBsin an upcoming subframe to carry a transport-block of that data from theUE and could transmit to the UE an advanced scheduling directive thatspecifies those PRBs, and the UE could then transmit the data to theaccess node in those PRBs.

For such scheduled downlink or uplink communication on PRBs, the accessnode and UE could use a modulation and coding scheme (MCS) that isselected based on the UE's wireless channel quality, which the accessnode could specify in its scheduling directive to the UE. In arepresentative implementation, the MCS could define a coding rate basedon the extent of error-correction coding data or the like that would betransmitted together with the user-plane data being communicated, and amodulation scheme that establishes how many bits of data could becarried by each resource element. When channel quality is better, theaccess node may direct use of a higher-order MCS that has a highercoding rate (e.g., with more error-correction coding) and/or hatsupports more bits per resource element, and when channel quality isworse, the access node may direct use of a lower-order MCS that may havea lower coding rate and/or supports fewer bits per resource element.

In practice, the access node could determine the MCS to be used use in agiven instance based on wireless channel quality reported by the UE.

For instance, as the access node serves the UE, the UE could transmitchannel quality reports to the access node periodically and/or as partof the UE's scheduling requests or other communications to the accessnode, with each report including a channel-quality indicator (CQI) valuerepresenting the UE's determined channel quality and perhaps one or moreother channel metrics such as downlink reference signal receive power(RSRP), signal-to-noise-plus interference ratio (SINR), or the like.When the access node schedules communications to or from the UE, theaccess node could then map the UE's latest reported CQI value to acorresponding MCS value using a standard CQI-MCS mapping table, and theaccess node could direct use of that MCS in the scheduling directivethat the access node sends to the UE. Communication could thus occurusing that directed MCS.

In addition, for uplink communication, the access node might also basethe determination of MCS on an evaluation of the UE's uplinktransmission power, namely, the extent to which the UE is transmittingwith sufficient power.

As the access node serves the UE, for instance, the access node and UEmay engage in an uplink power-control process through which the accessnode directs the UE incrementally increase or decrease its transmissionpower in an effort to keep the uplink receive power at a desired level.But the UE may be limited to a maximum transmission power level.Therefore, the UE may have a level of power-headroom that defines thedifference between (i) the transmission power that the UE should beusing based on the power control process and (ii) the UE's maximumtransmission power. A positive power-headroom value would mean that theUE has transmission power to spare and can increase its transmissionpower more if directed to do so, whereas a zero or negativepower-headroom value would mean that the UE has already reached itsmaximum transmission power level and may be unable to transmit withsufficient power.

When the UE sends a scheduling request to the access node, the UE couldinclude in the scheduling request a power-headroom report (PHR)indicating the UE's current power headroom. And the access node coulduse that reported power headroom as a basis to set or adjust the MCSthat the access node will direct the UE to use for uplink transmission.If the power headroom is negative, for instance, the access node mightartificially reduce the MCS-order from the MCS indicated by the UE'schannel quality report. Use of a lower-order MCS might be more robustand better able to facilitate successful uplink communication withconstrained uplink transmission power.

In practice, the uplink bandwidth of the carrier on which an access nodeserves a UE could pose an effective limit on the peak rate of datatransmission from the UE to the access node, as the uplink bandwidthwould contain only a limited number of PRBs per subframe or othertransmission time interval (TTI), with the data rate per PRB beingfurther limited based on the MCS set as discussed above for instance,and with the number of allocated PRBs being limited based on how manyother UEs the access node is concurrently serving on that uplinkchannel.

One way to help overcome this uplink data rate limitation is to have theaccess node serve the UE with uplink carrier aggregation, by serving theUE on uplink channels of multiple carriers concurrently. To provideuplink carrier-aggregation service for the UE, the access node could addone or more additional carriers to the UE's connection with the accessnode, and the access node could then schedule uplink communication fromthe UE to occur concurrently on the uplink channels of the multiplecarriers, with the UE transmitting some data on one or more PRBs of onecarrier's uplink channel concurrently with transmitting other data onone or more PRBs of another carrier's uplink channel.

In a representative uplink carrier-aggregation scenario, the UE would beserved on two carriers at once (as a “2CA” arrangement), with onecarrier being deemed a primary carrier or primary cell (PCell) and theother being deemed a secondary carrier or secondary cell (SCell). ThePCell could function as the anchor for certain control signaling relatedto the carrier-aggregation service, such as for scheduling requests andscheduling directives, and the SCell could function generally tosupplement the UE's uplink bandwidth so as to help provide the UE withincreased peak uplink data rate.

One technical problem that can occur with uplink carrier aggregation,however, is that the UE's limited uplink transmission power may strainthe UE's ability to transmit concurrently on the uplink channels of themultiple component carriers. When the UE transmits concurrently on PRBsof multiple uplink channels, the UE may need to distribute itstransmission power across those uplink channels, and so the UE's per-PRBtransmission power may be relatively low. This could be especiallyproblematic in a scenario where the UE has reached its maximumtransmission power and is strained to transmit with sufficient power inthe first place.

To help address this problem, the access node could apply anuplink-SCell-deconfiguration process by which, when the UE's reportedchannel quality becomes threshold low, the access node wouldautomatically release the UE's SCell—possibly transitioning the UE fromuplink-carrier-aggregation service to service on a single uplinkchannel. In particular, the access node could regularly evaluate theUE's reported channel quality (e.g., RSRP or CQI) as to the SCellspecifically or cooperatively as to the multiple carriers on which theUE is served, and when the channel quality becomes at least as low as athreshold level, UL-SCell-Deconfig, the access node could drop the UE'suplink SCell from the UE's connection, so as to help alleviate the UE'suplink power distribution problem.

Unfortunately, however, a further technical problem with this process isthat the access node may be preconfigured to apply a fixedUL-SCell-deconfig threshold that may not be optimal.

In practice, certain operational circumstances may benefit from theaccess node applying of a higher or lower UL-SCell-deconfig threshold.

By way of example, the type of communication in which the UE is engagedmay justify application of a higher or lower UL-SCell-deconfigthreshold. For instance, if the UE is engaged in relatively heavy uplinkcommunication such as uplink video streaming, it may be useful to applya lower UL-SCell-deconfig threshold in order to help maintain the UE'sSCell longer (requiring worse reported channel quality before releasingthe UE's uplink SCell) so that the UE could benefit more from theincreased uplink peak data rate provided by the SCell. Whereas, if theUE is engaged in relatively light uplink communication such as webbrowsing traffic, it may be useful to apply a higher UL-SCell-deconfigthreshold, to more readily release the UE's SCell so as to more readilyaddress the uplink-power-distribution problem noted above.

As another example, the UE's maximum transmission power level mayjustify application of a higher or lower UL-SCell-deconfig threshold. AUE's maximum transmission power may be indicated by the UE's powerclass. For instance, a standard-power UE may have a maximum transmissionpower of 23 dBm, whereas a high-power UE may have a maximum transmissionpower of 26 dBm. If a UE has a lower maximum transmission power level,then it may be useful to apply a higher UL-SCell-deconfig threshold,since the UE may be more susceptible to the uplink-power-distributionproblem noted above. Whereas, if a UE has a higher maximum transmissionpower level, then it may be useful to apply a lower UL-SCell-deconfigthreshold, since the UE may be less susceptible to theuplink-power-distribution problem.

Further, a preconfigured UL-SCell-deconfig threshold may not be optimalin terms of the access node's uplink spectral efficiency. Uplinkspectral efficiency of the access node is a measure of the quantity ofdata that the access node's uplink could carry per unit of frequencyspectrum per unit time, possibly measured as a quantity of bits perHertz per second across the multiple uplink carrier channels on whichthe access node is configured to operate. If the access node isconfigured to apply an UL-SCell-deconfig threshold that is too low, thenthe access node's served UEs may more often end up using a reduced-orderMCS, and the access node may therefore generally have undesirably lowspectral efficiency. If the access node's spectral efficiency is toolow, then a provider of the access node may be compelled to addadditional uplink spectrum to the access node, which may be expensiveand therefore undesirable.

Disclosed herein is a technical solution to help address these problems.In accordance with the disclosure, an access node will dynamically varythe UL-SCell-deconfig threshold that the access node applies, with thedynamic varying being based upon operational circumstances and/or anevaluation of the access node's spectral efficiency.

In one respect, the access node could dynamically vary theUL-SCell-deconfig threshold that the access node applies, with thedynamic varying being based on operational circumstances such as thetype of communication in which the UE is engaged and/or based on theUE's power class.

For example, the access node could determine if the UE is engaged inrelatively heavy uplink communication or rather relatively light uplinkcommunication, and the access node could select an UL-SCell-deconfigthreshold based on that determination and could apply the selectedUL-SCell-deconfig threshold to control whether and when to release anSCell from the UE's connection. If the UE is engaged in relatively heavyuplink communication rather than relatively light uplink communication,then the access node could select and apply a first UL-SCell-deconfigthreshold rather than a second UL-SCell-deconfig threshold based on thefirst UL-SCell deconfig threshold being lower than the secondUL-SCell-deconfig threshold. Whereas, if the UE is engaged in relativelylight uplink communication rather than relatively heavy uplinkcommunication, then the access node could select and apply the secondUL-SCell-deconfig threshold rather than the first UL-SCell-deconfigthreshold based on the second UL-SCell deconfig threshold being higherthan the second UL-SCell-deconfig threshold.

Alternatively, the access node might generally be set to apply a defaultUL-SCell-deconfig threshold and may dynamically switch to apply anUL-SCell-deconfig threshold that is lower or higher than the defaultUL-SCell-deconfig threshold based on a determination of the type ofcommunication in which the UE is engaged. For instance, if the UE isengaged in relatively heavy uplink communication, then the access nodemay responsively switch to apply an UL-SCell-deconfig threshold that islower than the default UL-SCell-deconfig threshold. Whereas, if the UEis engaged in relatively light uplink communication, then the accessnode may responsively switch to apply an UL-SCell-deconfig thresholdthat is higher than the default UL-SCell-deconfig threshold.

As another example, the access node could determine the UE's powerclass, and the access node could select an UL-SCell-deconfig thresholdbased on the determined UE power class and could apply the selectedUL-SCell-deconfig threshold to control whether and when to release anSCell from the UE's connection. If the UE is a high-power UE rather thana standard-power UE, then the access node could select and apply a firstUL-SCell-deconfig threshold rather than a second UL-SCell-deconfigthreshold based on the first UL-SCell deconfig threshold being lowerthan the second UL-SCell-deconfig threshold. Whereas, if the UE is astandard-power UE rather than a high-power UE, then the access nodecould select and apply the second UL-SCell-deconfig threshold ratherthan the first UL-SCell-deconfig threshold based on the second UL-SCelldeconfig threshold being higher than the second UL-SCell-deconfigthreshold.

Alternatively or additionally, the access node might generally be set toapply a default UL-SCell-deconfig threshold and may dynamically switchto apply an UL-SCell-deconfig threshold that is lower or higher than thedefault UL-SCell-deconfig threshold based on a determination of the UE'spower class. For instance, if the UE is a high-power UE, then the accessnode may responsively switch to apply an UL-SCell-deconfig thresholdthat is lower than the default UL-SCell-deconfig threshold. Whereas, ifthe UE is a standard-power UE, then the access node may responsivelyswitch to apply an UL-SCell-deconfig threshold that is higher than thedefault UL-SCell-deconfig threshold.

Further, in another respect, the access node could dynamically vary theUL-SCell-deconfig threshold that the access node applies, with thedynamic varying being based on an evaluation of the access node's uplinkspectral efficiency. Here, for instance, the access node could beconfigured with an uplink-spectral-efficiency set point that defines anoptimal desired level of uplink spectral efficiency. Further, the accessnode could be set with an initial UL-SCell-deconfig threshold to applygenerally (e.g., as a default UL-SCell-deconfig threshold for use whenserving UEs). And the access node could then regularly evaluate itsactual uplink spectral efficiency and could dynamically adjust theUL-SCell-deconfig threshold, or select an UL-SCell-deconfig threshold toapply, based on the current level of its uplink spectral efficiency.

With this implementation, the access node could measure its uplinkspectral efficiency over a sliding window of time, generally across themultiple carriers on which the access node is configured to operate. Andthe access node could regularly compare its latest measure of uplinkspectral efficiency with its uplink-spectral-efficiency set point.

If and when the access node thereby determines that its uplink spectralefficiency is less than its uplink-spectral-efficiency set point, theaccess node could responsively increase its UL-SCell-deconfig thresholdor select a higher UL-SCell-deconfig threshold to apply. The access nodecould then apply the increased UL-SCell-deconfig threshold, which mayresult in the access node more readily releasing UEs' SCells and maythereby help reduce the extent to which UEs will face the MC S-reductionnoted above. Reducing the extent of MCS reduction may in turn helpincrease the access node's uplink spectral efficiency, approaching theuplink-spectral-efficiency set point.

Whereas, if and when the access node thereby determines that its uplinkspectral efficiency is greater than its uplink-spectral-efficiency setpoint, the access node could responsively decrease its UL-SCell-deconfigthreshold or select a lower UL-SCell-deconfig threshold to apply. Theaccess node could then apply the decreased UL-SCell-deconfig threshold,which may result in the access node less readily releasing UEs' SCellsand may thereby increase the extent to which UEs will face theMCS-reduction noted above. Increasing the extent of MCS reduction may inturn help decrease the access node's uplink spectral efficiency,likewise approaching the uplink-spectral-efficiency set point.

These as well as other aspects, advantages, and alternatives will becomeadditionally apparent to those of ordinary skill in the art by readingthe following detailed description, with reference where appropriate tothe accompanying drawings. Further, it should be understood that thedescriptions provided in this overview and below are intended toillustrate the invention by way of example only and not by way oflimitation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a simplified block diagram of a network arrangement in whichaspects of the present disclosure can be implemented.

FIG. 2 is a flow chart depicting a method that can be carried out inaccordance with the disclosure.

FIG. 3 is another flow chart depicting a method that can be carried outin accordance with the disclosure.

FIG. 4 is another flow chart depicting a method that can be carried outin accordance with the disclosure.

FIG. 5 is another flow chart depicting a method that can be carried outin accordance with the disclosure.

FIG. 6 is a simplified block diagram of an access node operable inaccordance with the disclosure.

DETAILED DESCRIPTION

Referring to the drawings, as noted above, FIG. 1 is a simplified blockdiagram of an example wireless communication system in which variousdisclosed features can be implemented. It should be understood, however,that numerous variations from this and other disclosed arrangements andoperations are possible. For example, elements or operations could beadded, removed, combined, distributed, re-ordered, or otherwisemodified. In addition, operations described as being performed by one ormore entities could be implemented in various ways, such as by aprocessor executing instructions stored in non-transitory data storage,along with associated circuitry or other hardware, for instance.

As shown in FIG. 1, the example wireless communication system includes arepresentative access node 12 that is configured to provide service onmultiple carriers 14, each of which could be FDD or TDD and thereforeinclude separate downlink and uplink channels or a shared channelmultiplexed over time for downlink and uplink use. Shown operatingwithin coverage of the access node are then a plurality of UEs 16, whichcould be devices of the type discussed above, among other possibilities.

The access node 12 could be a macro access node of the type configuredto provide a wide range of coverage, with an antenna structure mountedon a tower or other tall structure. Alternatively, the access node couldtake other forms, such as a small cell access node, a repeater, afemtocell access node, or the like, which might be configured to providea smaller range of coverage. The access node could be configured tooperate according to any of the radio access technologies describedabove, among other possibilities.

The access node is shown coupled with a core network 18, which could bean enhanced packet core (EPC) network, a next generation core (NGC)network, or another network including components that support anapplicable radio access technology and that may provide connectivitywith at least one transport network 20, such as the Internet.

In an example implementation as shown, the core network 18 includes aserving gateway (SGW) 22, a packet data network gateway (PGW) 24, amobility management entity (MME) 26, and a home subscriber server (HSS)28. In particular, the access node 12 has an interface with the SGW 22,the SGW 22 has an interface with the PGW 24, and the PGW 24 providesconnectivity with the transport network 20. Further, the access node 12has an interface with the MME 26, and the MME 26 has interfaces with theSGW 22 and the HSS 28. These various interfaces could be virtual packettunnels defined within the core network.

With this arrangement, the SGW and PGW cooperatively provide user-planeconnectivity between the access node 12 and the transport network 20, toenable a UE served by the access node to engage in communication on thetransport network. And the MME 26 operates as a controller to carry outoperations such as coordinating UE attachment and setup of user-planebearers. Further, the HSS 28 includes or has access to a data storecontaining UE capabilities and service profile data and may work withthe MME 26 to facilitate UE authentication.

As discussed above, the air interface on each of the access node'scarriers 14 could be structured to define various air-interfaceresources.

For instance, in the time domain, the air interface could define acontinuum of 10-millisecond (ms) frames, each divided into ten 1-mssubframes, and each subframe could be further divided into a number oftimeslots, each additionally divided into symbol time segments. And inthe frequency domain, the carrier bandwidth could be divided intosubcarriers with specified subcarrier spacing on the order of 15 to 240kHz. With this arrangement, the air interface on each carrier woulddefine the above-noted array of resource elements each occupying asubcarrier and symbol time segment, and the access node 12 and UEs couldcommunicate with each other through modulation of the subcarriers tocarry data in those resource elements. Variations of this arrangementare possible as well.

Further, particular groupings of resource elements on the air interfaceof each carrier could be grouped together to define the PRBs discussedabove. In an example implementation, each PRB could span one timeslot inthe time domain and a group of subcarriers in the frequency domain.Depending on the carrier bandwidth, the air interface could thus supporta certain number of such PRBs across the bandwidth of the carrier withineach timeslot or within each subframe. Further, certain resourceelements or PRBs could be reserved for use to carry particular types ofdata, such as control signaling and/or user-plane communications asnoted above.

In line with the discussion above, when a UE enters into coverage of theaccess node, the UE could detect coverage of the access node on aparticular carrier. And the UE could then engage in random accesssignaling and RRC signaling with the access node 12 to connect with theaccess node on the carrier, thus putting the UE in an RRC-connectedmode.

Once the UE is connected with the access node 12, the UE could thentransmit to the access node an attach request, which the access nodecould forward to the MME 26 for processing. After working with the HSS28 to authenticate the UE, the MME 26 could coordinate setup for the UEof one or more user-plane bearers, to enable the UE to engage incommunication on the transport network 20. And the access node couldestablish for the UE a context record indicating operational state ofthe UE, including an indication of the carrier on which the UE isconnected and an indication of each user-plane bearer that is configuredfor the UE. Further, the access node could receive from the UE and/orthe HSS (via the MME) a set of capabilities, configuration, and profiledata for the UE and could store that data in the context record forreference while serving the UE.

Each user-plane bearer that the MME 26 configures for the UE could havea respective quality-of-service class level, having a correspondingquality-of-service class indicator (QCI) value that is associated withthe type of communication the bearer would carry, and the access nodemight record that QCI value in the UE's context record. By default, theMME may set up for the UE a best-efforts bearer (QCI 9) for use to carrygeneral Internet communications such as web-browsing traffic, messagingtraffic, or the like. Further, initially or in response to othersignaling from the UE or other entities indicating that the UE willengage in a particular type of communication, the MME might set up oneor more other appropriate bearers for the UE, such as a QCI 2 bearer foruse to carry conversational video communications, a QCI 3 bearer for useto carry real-time gaming traffic, and/or a QCI 7 bearer to carry livevideo streaming traffic, among other possibilities.

As discussed above, once the UE is connected with the access node on acarrier and has one or more established bearers, the access node couldthen serve the UE with wireless data communications. For instance, asdiscussed above, when the UE has data to transmit, the UE could transmitto the access node a scheduling request, including a BSR and PHR. Andthe access node could then allocate one or more uplink PRBs in anupcoming subframe for carrying a transport block of data from the UE andcould transmit to the UE a DCI message that designates those upcomingPRBs. The UE could then accordingly transmit the transport block to theaccess node in the designated PRBs.

Further, as noted above, while the access node is serving the UE, the UEcould report to the access node periodically and/or within the UE'sscheduling requests or other signaling an indication of the UE'sdetermined channel quality, such as CQI or RSRP for instance. And asnoted above, the access node could use that channel quality report,possibly together with the UE's PHR or other information, as a basis tothe MCS that the access node may designate in its uplink schedulingdirectives to the UE.

In addition, initially upon UE connection or subsequently while theaccess node is serving the UE on a carrier, the access node couldconfigure uplink carrier-aggregation service for the UE.

To invoke uplink carrier aggregation service for the UE, the access nodecould first engage in RRC signaling with the UE to cause the UE to scanfor coverage on the access node's carriers 14 and to report thresholdstrong coverage on a given such other carrier. The access node couldthen add at least the uplink channel of that other carrier to the UE'sconnection, designating one of the UE's serving carriers as the UE'sPCell and designating another of the UE's serving carriers as the UE'sSCell for an example 2CA implementation. For instance, the access nodecould update the UE's context record to indicate that the access node isnow serving the UE with uplink carrier aggregation on the uplinkchannels of the PCell and the SCell. And the access node could engage inRRC signaling with the UE to inform the UE that the access node is nowserving the UE with uplink carrier aggregation on those two uplinkchannels.

With uplink carrier aggregation so configured, the access node couldthen serve the UE accordingly. In line with the discussion above, whenthe UE has data to transmit, the UE could send a scheduling request(e.g., with BSR, CQI, and PHR) on the UE's PCell. The access node couldthen allocate a uplink PRBs distributed across the uplink channels in anupcoming subframe to carry the data from the UE to the access node. Andthe access node could transmit to the UE a DCI specifying a set of PRBsrespectively on each of the uplink channels on which the UE shouldtransmit the data, and specifying an MCS for the UE to use for thetransmission. The UE could then accordingly transmit the data to theaccess node concurrently on a set of PRBs on the UE's PCell and a set ofPRBs on the UE's SCell.

In practice, the access node may serve multiple UEs 16 concurrently,each with either single-uplink-carrier service oruplink-carrier-aggregation service, possibly on various ones orcombinations of the access node's carriers 14. On a given carrier, theaccess node could therefore apply a scheduling algorithm that seeks tofairly allocate the limited number of uplink PRBs of the carrier amongthe various served UEs, to enable each UE to engage in uplinkcommunication as appropriate.

Further, as discussed above, when the access node is serving a given UEwith uplink carrier aggregation, the access node could automaticallydeconfigure an uplink SCell of a UE's connection if and when the UEreports threshold poor channel quality, namely, channel quality that isat least as poor as an UL-SCell-deconfig threshold. If the UE is servedwith uplink carrier aggregation on just two carrier's uplink channels(i.e., uplink 2CA), this could involve deconfiguring the single uplinkSCell of the UE's connection. Whereas, if the UE is served with uplinkcarrier aggregation on more than two carriers' uplink channels (e.g.,uplink 3CA or greater), this could involve deconfiguring all of the UE'suplink SCells or perhaps deconfiguring just one or another proper subsetof the UE's uplink SCells.

The UL-SCell-deconfig threshold could vary based on the type of UEchannel quality metric used. For instance, if the UE channel qualitymetric is RSRP, then the UL-SCell-deconfig metric might be an RSRP valuedeemed sufficiently low to justify deconfiguring the UE's uplink SCell.Examples of such RSRP threshold values might be in the range of −110 dBmto −85 dBm, among other possibilities. Whereas if the UE channel qualitymetric is QCI, then the UL-SCell-deconfig metric might be a QCI valuedeemed likewise sufficiently low to justify deconfiguring the UE'suplink SCell.

Deconfiguring the UE's uplink SCell could involve reconfiguring the UE'sRRC connection to operatively remove the uplink SCell from theconnection.

Operatively removing the uplink SCell from the UE's connection couldinvolve setting the access node to stop allocating uplink PRBs of thatSCell to the UE. The access node could update the UE's context record toindicate this and perhaps signal accordingly to the UE, and the accessnode would then accordingly not allocate uplink PRBs of that SCell foruse by the UE, rather allocating to the UE uplink PRBs of just the UE'sPCell (and perhaps any other non-deconfigured SCell).

Further, where feasible, operatively removing the uplink SCell from theUE's connection could involve actually removing the uplink channel ofthe SCell from the UE's connection. For instance, if the UE's connectionencompasses an FDD SCell that includes separate downlink and uplinkfrequency channels, this could involve the access node removing from theconnection the uplink channel of that SCell and leaving in theconnection the downlink channel of the SCell, or removing the SCellaltogether from the UE's connection. Here too, the access node couldupdate the UE's context record to indicate and could signal accordinglyto the UE. And the access node could then proceed to serve the UE on thefrequency channels remaining in the UE's connection.

In line with the discussion above, the access node 12 in an exampleimplementation will dynamically set (e.g., select, adjust, or otherwiseconfigure) the UL-SCell-deconfig threshold based upon operationalcircumstances (e.g., one or more such circumstances) and/or anevaluation of the access node's spectral efficiency.

As to operational circumstances, as discussed above, the access nodecould dynamically set the UL-SCell-deconfig threshold to apply for agiven UE, with the setting being based on the type of communication inwhich the UE is engaged, such as whether the type of communication isuplink heavy or rather uplink light.

As discussed above if the access node determines that the communicationtype is uplink heavy, then, based at least in part on thatdetermination, the access node could responsively apply a lowerUL-SCell-deconfig threshold (e.g., on the order of −100 dBm to −95 dBm).Whereas, if the access node determines that the communication type isuplink light, then the access node could responsively apply a higherUL-SCell-deconfig threshold (e.g., on the order of −90 dBm to −85 dBm).

The type of communication in which the UE is engaged could be the typeof communication in which the UE is currently engaged or the type ofcommunication in which the UE is about to be engaged, among otherpossibilities. The access node could determine the type of communicationin which the UE is engaged in various ways. By way of example, theaccess node could deduce the type of communication based on the QCIlevel of a bearer currently established for the UE, or by evaluating(e.g., with deep-packet inspection) communication-session setupsignaling that passes to or from the UE via the access node and thatindicates the type of communication, among other possibilities.

The access node could then be configured with mapping data (e.g., atable or other data structure, and/or associated program logic) thatmaps particular types of communications with corresponding indicationsof how uplink-heavy or uplink-light the type of communication tends tobe. That way, upon determining a type of communication in which the UEis engaged, the access node could refer to that mapping data todetermine whether the type of communication is uplink heavy or ratheruplink light. And the access node could accordingly select anUL-SCell-deconfig threshold to apply for the UE.

Alternatively, the access node could be configured with mapping datathat maps particular types of communications directly with correspondingUL-SCell-deconfig thresholds to apply, with the mappings possibly beingestablished based on engineering input in view of uplink heaviness orlightness and/or one or more other factors. Upon determining the type ofcommunication in which the UE is engaged, the access node could thenrefer to this mapping data to directly determiner what UL-SCell-deconfigthreshold to apply, and the access node could apply thatUL-SCell-deconfig threshold for the UE.

Still alternatively, the access node could determine whether the UE isengaged in uplink heavy or uplink light communication by monitoring theactual extent of uplink communication from the UE, such as the actualrate of uplink communication from the UE per unit time over a recentsliding window. That actual extent of uplink communication from the UEmay be uplink-heavy communication, which could lead the access node toapply a lower UL-SCell-deconfig threshold, or uplink-lightcommunication, which could lead the access node to apply a higherUL-SCell-deconfig threshold.

Note also that, through these or other techniques, the access node couldselect an UL-SCell-deconfig threshold from a range of UL-SCell-deconfigthresholds based on how heavy or how light the UE's communication is.For instance, if the access node determines that the UE's uplinkcommunication is very heavy, then the access node might select anUL-SCell-deconfig threshold of −100 dBm; if the access node determinesthat the UE's uplink communication is somewhat heavy, then the accessnode might select an UL-SCell-deconfig threshold of −95 dBm; if theaccess node determines that the UE's uplink communication is somewhatlight, then the access node might select an UL-SCell-deconfig thresholdof −90 dBm; and if the access node determines that the UE's uplinkcommunication is very light, then the access node might select anUL-SCell-deconfig threshold of −85 dBm.

Alternatively or additionally as to operational circumstances, as alsodiscussed above, the access node could dynamically set theUL-SCell-deconfig threshold to apply for a given UE, with the settingbeing based on the power class of the UE, such as whether the UE is astandard-power UE or rather a high-power UE.

In practice, the UE's capabilities, configuration, and/or profile datathat the access node obtains and stores in the UE's context record mightindicate the UE's power class. The access node could therefore refer tothat data to determine the UE's power class and could set theUL-SCell-deconfig to apply for the UE based on that determined powerclass.

In an example implementation, the access node could be configured withmapping data (e.g., a table or other data structure, and/or associatedprogram logic) that maps particular UE power classes to particularUL-SCell-deconfig thresholds. For instance, the mapping data couldspecify that, if the UE is a standard-power UE, then the access nodeshould apply a UL-SCell-deconfig threshold of −85 dBm to −90 dBm. Andthe mapping data could specify that, if the UE is a high-power UE, thenthe access node should apply a UL-SCell-deconfig threshold of −95 dBm to−100 dBm. Upon determining the UE's power class, the access node couldthus refer to that data to determine a corresponding UL-SCell-deconfigthreshold to apply and could proceed to apply that UL-SCell-deconfigthreshold for the UE.

As further noted above, the access node could carry out this dynamicsetting of UL-SCell-deconfig to apply for a particular UE in a scenariowhere the access node is set to apply a default UL-SCell-deconfigthreshold and the access node then transitions to apply a differentUL-SCell-deconfig threshold on one or more of these bases. For instance,based at least in part on a determination that the UE is engaged in athreshold heavy uplink communication, the access node could transitionfrom applying the default UL-SCell-deconfig threshold to applying alower UL-SCell-deconfig threshold. Or based at least in part on adetermination that the UE is a high-power UE rather than astandard-power UE, the access node could transition from applying thedefault UL-SCell-deconfig threshold to applying a lowerUL-SCell-deconfig threshold. Other examples are possible as well.

Alternatively or additionally, as to spectral efficiency, as discussedabove, the access node could dynamically vary a UL-SCell-deconfigthreshold that the access node generally applies for its served UEs(e.g., as the default UL-SCell-deconfig threshold noted above) based onan evaluation of the access node's uplink spectral efficiency. Inpractice, for instance, the access node could periodically carry outthis process, to adjust the UL-SCell-deconfig threshold in an effort toachieve a desired level of uplink spectral efficiency.

As noted above, for this implementation, the access node could beconfigured with an uplink-spectral-efficiency set point against whichthe access node would compare its current level of uplink spectralefficiency. An example uplink-spectral-efficiency set point could be 5megabits/second/Hertz (Mbps/Hz), but other values could be set byengineering design.

The access node could then track its uplink spectral efficiencycooperatively across the uplink channels of the access nodes variouscarriers 14. For instance, the access node could determine the quantityof data that is communicated per second cooperatively across the accessnode's various uplink channels and could divide that data rate by thesum total of the uplink channels' bandwidth, to compute the accessnode's uplink spectral efficiency.

In line with the discussion above, dynamically adjusting theUL-SCell-deconfig threshold based on uplink spectral efficiency couldbegin with the access node being set to apply an initialUL-SCell-deconfig threshold. This initial UL-SCell-deconfig thresholdcould be the UL-SCell-deconfig threshold that the access node is set toapply at any given time that this process may apply.

For each of one or more times that the access node determines the accessnode's actual uplink spectral efficiency, the access node could thencompare that determined uplink spectral efficiency with theuplink-spectral-efficiency set point and, based on the comparison, couldthen adjust the UL-SCell-deconfig threshold. Namely, as discussed above,if and when the access node determines that its actual uplink spectralefficiency is lower than the uplink-spectral-efficiency set point, theaccess node could responsively increase the UL-SCell-deconfig thresholdthat the access node applies generally for its served UEs. Whereas ifand when the access node determines that its actual uplink spectralefficiency is higher than the uplink-spectral-efficiency set point, theaccess node could responsively decrease the UL-SCell-deconfig thresholdthat the access node applies generally for its served UEs.

Each incremental change that the access node makes to theUL-SCell-deconfig threshold in this process could be by a set amount(e.g., by 0.5 dBm or 1 dBm). Alternatively, the access node could setthe magnitude of the incremental change based on the magnitude of thedifference between the access node's determined uplink spectralefficiency and the uplink-spectral-efficiency set point. For instance,for a small difference, the access node might make a small incrementalchange (e.g., about 0.5 dBm), whereas for a larger difference, theaccess node might make a larger incremental change (e.g. about 2 dBm).Other examples are possible as well.

Applying this process iteratively, the access node could thus learn whatUL-SCell-deconfig threshold could help achieve a desired level ofspectral efficiency when applied for UEs served by the access node. Byway of example, if a lot of UEs served by the access node engage inuplink heavy communication, and if the UL-SCell-deconfig threshold istoo high, those UEs may tend to face reduced-order MCS, and so theaccess node's overall uplink spectral efficiency may be lower. Throughthis iterative process, that lower uplink spectral efficiency may resultin increasing the UL-SCell-deconfig threshold, which may in turn resultin more readily deconfiguring the uplink SCell of the served UEs,thereby helping to decrease the extent of MCS-reduction, which may inturn increase the access node's uplink spectral efficiency.

FIG. 2 is next a flow chart depicting a method that could be carried outin line with the discussion above, to help control uplinkcarrier-aggregation service with an UL-SCell-deconfig threshold to beapplied for a given UE being set based on one or more operationalcircumstances of the UE. Features of this method could be carried out bythe access node itself or by one or more other entities operating onbehalf of the access node, among other possibilities.

As shown in FIG. 2, at block 30, the method includes the access nodeserving the UE with uplink carrier-aggregation over a connection thatencompasses multiple uplink channels including a primary uplink channel(uplink PCell) and a secondary uplink channel (uplink SCell). At block32, the method includes the access node dynamically setting achannel-quality threshold (e.g., UL-SCell-deconfig) applicable tocontrol when to deconfigure the uplink SCell from service of the UE,with the dynamically setting of the channel-quality threshold includingsetting the channel-quality threshold to a value selected based on oneor more operational circumstances of the UE. And at block 34, the methodincludes the access node applying the dynamically set channel-qualitythreshold to control when to deconfigure the uplink SCell from serviceof the UE.

In line with the discussion above, the channel-quality threshold in thismethod could be a downlink channel quality value, such as RSRP, CQI, orthe like. And the act of applying the dynamically set channel-qualitythreshold to control when to deconfigure the uplink SCell from serviceof the UE could involve (i) receiving from the UE a report of downlinkchannel quality, (ii) making a determination of whether the reporteddownlink channel quality is at least as low as the dynamically setchannel-quality threshold, and (iii) responsive to the determinationbeing affirmative, deconfiguring the uplink SCell from service of theUE.

As discussed above, the act of setting the channel-quality threshold tothe value selected based on one or more operational circumstances of theUE could involve setting the channel-quality threshold to a valueselected based on a type of communication in which the UE engages. Forinstance, this could involve (i) making a determination of whether thetype of communication is uplink-heavy or rather uplink-light, (ii) ifthe determination is that the type of communication is uplink-heavyrather than uplink-light, then, based on the determination, selecting asthe channel-quality threshold a first channel-quality threshold ratherthan a second channel-quality threshold based on the firstchannel-quality threshold being lower than the second channel-qualitythreshold, and (iii) if the determination is that the type ofcommunication is uplink-light rather than uplink-heavy, then, based onthe determination, selecting as the channel-quality threshold the secondchannel-quality threshold rather than a first channel-quality thresholdbased on the second channel-quality threshold being higher than thefirst channel-quality threshold.

Further, as discussed above, the act of setting the channel-qualitythreshold to the value selected based on the type of communication inwhich the UE engages comprises (i) operating with the channel-qualitythreshold set to a default (e.g., initially set) value, (ii) making adetermination of whether the type of communication is uplink-heavyrather than uplink-light, and (iii) responsive to the determinationbeing affirmative, transitioning from operating with the channel-qualitythreshold set to the default value to operating instead with thechannel-quality threshold set to a value lower than the default value.

Alternatively or additionally, as discussed above, the act of settingthe channel-quality threshold to the value selected based on one or moreoperational circumstances of the UE could involve setting thechannel-quality threshold to a value selected based on a power class ofthe UE. Here, for instance, the power class of the UE could define amaximum transmission power of the UE and could be (i) standard-power or(ii) high-power, with high-power defining a higher maximum transmissionpower than the standard-power.

In that case, the act of setting the channel-quality threshold to avalue selected based on the power class of the UE could involve (i)making a determination of whether the power class of the UE isstandard-power or rather high-power, (ii) if the determination is thatthe power class of the UE is standard-power rather than high-power,then, based on the determination, setting the channel-quality thresholdto a first value rather than a second value based first value beinghigher than the second value, and (iii) if the determination is that thepower class of the UE is high-power rather than standard-power, then,based on the determination, setting the channel-quality threshold to thesecond value rather than the firs value based second value being lowerthan the first value.

Further, the act of setting the channel-quality threshold to a valueselected based on the power class of the UE could involve (i) operatingwith the channel-quality threshold set to a default value (e.g., initialvalue), (ii) making a determination that the power class of the UE ishigh-power, and (iii) responsive to the determination, transitioningfrom operating with the channel-quality threshold set to the defaultvalue to operating instead with the channel-quality threshold set to avalue lower than the default value.

FIG. 3 is another flow chart depicting a method that could be carriedout in line with the with the discussion above, to help control uplinkcarrier-aggregation service with an UL-SCell-deconfig threshold to beapplied for a given UE being set based on the type of communication inwhich the UE is engaged. Here too, features of this method could becarried out by the access node itself or by one or more other entitiesoperating on behalf of the access node, among other possibilities.

As shown in FIG. 3, at block 36, the method includes the access nodeserving a UE is with uplink carrier-aggregation over a connectionencompassing multiple uplink channels including an uplink PCell and anuplink SCell. At block 38, the method further includes dynamicallysetting a channel-quality threshold (e.g., UL-SCell-deconfig) applicableto control when to deconfigure the uplink SCell from service of the UE,with the dynamically setting of the channel-quality threshold including(i) determining a type of communication in which the UE engages and (ii)using mapping data to map the determined type of communication to thechannel-quality threshold applicable to control when to deconfigure theuplink SCell from service of the UE. And at block 40, the methodincludes the access node applying the dynamically set channel-qualitythreshold to control when to deconfigure the uplink SCell from serviceof the UE.

Various features discussed above can be applied in this context as well,and vice versa.

FIG. 4 is next a flow chart depicting a method that could be carried outin line with the discussion above, to help control uplinkcarrier-aggregation service with an UL-SCell-deconfig threshold to beapplied generally by the access node being dynamically set based onuplink spectral efficiency of the access node. Here too, features ofthis method could be carried out by the access node itself or by one ormore other entities operating on behalf of the access node, among otherpossibilities.

As shown in FIG. 4, at block 42, the method includes the access nodeserving the UE with uplink carrier-aggregation over a connectionencompassing multiple uplink channels including an uplink PCell and anuplink SCell. Further, at block 44, the method includes the access nodedynamically setting a channel-quality threshold (e.g.,UL-SCell-deconfig) applicable to control when to deconfigure the uplinkSCell from service of the UE, with the dynamically setting of thechannel-quality threshold including adjusting the channel-qualitythreshold based on uplink spectral efficiency of the access node. And atblock 46, the method includes the access node applying the dynamicallyset channel-quality threshold to control when to deconfigure the uplinkSCell from service of the UE.

In line with the discussion above, as in the implementations above, thechannel-quality threshold in this method could be a downlink channelquality value (e.g., RSRP or CQI, among other possibilities). And theact of applying the dynamically set channel-quality threshold to controlwhen to deconfigure the uplink SCell from service of the UE couldinvolve (i) receiving from the UE a report of downlink channel quality,(ii) making a determination of whether the reported downlink channelquality is at least as low as the dynamically set channel-qualitythreshold, and (iii) responsive to the determination being affirmative,deconfiguring the uplink SCell from service of the UE.

Further, as discussed above, the act of adjusting the channel-qualitythreshold based on uplink spectral efficiency of the access node couldinvolve iteratively (i) computing uplink spectral efficiency of theaccess node (perhaps cooperatively across multiple carriers on which theaccess node is configured to operate), (ii) comparing the computeduplink spectral efficiency of the access node with anuplink-spectral-efficiency set point, (iii) based on the comparing,adjusting the channel-quality threshold.

And in this iterative process, the act of adjusting the channel-qualitythreshold based on the comparing could involve (i) making adetermination, based on the comparing, of whether the computed uplinkspectral efficiency of the access node is greater than or less than theuplink-spectral-efficiency set point, (ii) if the determination is thatthe computed uplink spectral efficiency of the access node is greaterthan the uplink-spectral-efficiency set point, then, based on thedetermination, decreasing the channel-quality threshold, and (iii) ifthe determination is that the computed uplink spectral efficiency of theaccess node is less than the uplink-spectral-efficiency, then, based onthe determination, increasing the channel-quality threshold. And the actof iteratively adjusting of the channel-quality threshold could startwith an initial channel-quality threshold value.

Still further, as discussed above, the method could include the accessnode applying the dynamically configured channel-quality threshold foreach of a plurality of UEs that the access node serves with uplinkcarrier aggregation.

Various features discussed above can be applied in this context as well,and vice versa.

FIG. 5 is next a flow chart depicting a method that could be carried outin line with the discussion above, to help control wirelesscommunication service by an access node. Here too, features of thismethod could be carried out by the access node itself or by one or moreother entities operating on behalf of the access node, among otherpossibilities.

As shown in FIG. 5, at block 48, the method includes the access nodedynamically setting a channel-quality threshold (e.g.,UL-SCell-deconfig) applicable to control when to deconfigure uplinkcarrier aggregation service provided by the access node, with thedynamically setting of the channel-quality threshold being based onuplink spectral efficiency of the access node. And at block 50, themethod includes the access node applying the dynamically setchannel-quality threshold to control when to deconfigure the uplinkcarrier aggregation service for each of plurality of UEs served by theaccess node.

Various features discussed above can be applied in this context as well,and vice versa.

Finally, FIG. 6 is a simplified block diagram of an access node thatcould carry out various features described herein. As shown in FIG. 5,the example access node includes a wireless communication interface 52,a backhaul communication interface 54, and a controller 56, all of whichcould be integrated together and/or communicatively linked by a network,system bus, or other connection mechanism 58.

Wireless communication interface 52 includes a radio 60 and antennastructure 62, among other components, cooperatively enabling the accessnode to provide wireless service on a plurality of carriers. Forinstance, the radio could operate to interface between RF signals andbaseband signals. And the antenna structure 62 could comprise aplurality of antennas (e.g., an antenna array) through which the accessnode communicates over the air interface.

Backhaul communication interface 54 could be a network communicationinterface (e.g., an Ethernet network interface port and/or connection)through which the access node can communicate with various other networkentities, such as entities on a core network for instance.

And controller 56, which could comprise a processing unit 64 (e.g., oneor more microprocessors or other processors), data storage 66 (e.g., oneor more volatile and/or non-volatile storage units, such as magnetic,optical or flash storage), and program instructions 68 stored in thedata storage and executable by the processing unit, or could take otherforms, could be operable to cause carry out various operations asdescribed herein, thus causing the access node to carry out the variousoperations.

In line with the discussion above, for instance, the controller beconfigured to control service of a user equipment device (UE) when theUE is served by the access node with uplink carrier-aggregation over aconnection encompassing multiple uplink channels including an uplinkPCell and an uplink SCell. By way of example, the controller could beconfigured to dynamically set a channel-quality threshold applicable tocontrol when to deconfigure the uplink SCell from service of the UE, andto apply the dynamically set channel-quality threshold to control whento deconfigure the uplink SCell from service of the UE.

As discussed above, the act of dynamically setting of thechannel-quality threshold could include setting the channel-qualitythreshold to a value selected based on one or more operationalcircumstances of the UE, such as based on the type of communication inwhich the UE engages or based on a power class of the UE. For instance,the controller could be configured to determine a type of communicationin which the UE engages and to use mapping data to map the determinedtype of communication to the channel-quality threshold applicable tocontrol when to deconfigure the uplink SCell from service of the UE.

And as further discussed above, the act of dynamically setting the achannel-quality threshold could involve adjusting the channel-qualitythreshold based on uplink spectral efficiency of the access node. Forinstance, the controller could be configured to iteratively (i) computeuplink spectral efficiency of the access node, (ii) compare the computeduplink spectral efficiency of the access node with anuplink-spectral-efficiency set point, (iii) based on the comparing,adjust the channel-quality threshold.

Various features discussed above can be applied in this context as well,and vice versa.

Exemplary embodiments have been described above. Those skilled in theart will understand, however, that changes and modifications may be madeto these embodiments without departing from the true scope and spirit ofthe invention.

We claim:
 1. An access node comprising: a wireless communicationinterface including an antenna structure through which to providewireless service on a plurality of carriers; a backhaul communicationinterface through which to communicate on a core network; and acontroller configured to control service of a user equipment device (UE)when the UE is served by the access node with uplink carrier-aggregationover a connection encompassing multiple uplink channels including aprimary uplink channel (uplink PCell) and a secondary uplink channel(uplink SCell), wherein the controller is configured to dynamically seta channel-quality threshold applicable to control when to deconfigurethe uplink SCell from service of the UE, wherein dynamically setting thechannel-quality threshold comprises setting the channel-qualitythreshold to a value selected based on one or more operationalcircumstances of the UE, wherein setting the channel-quality thresholdto the value selected based on the one or more operational circumstancesof the UE comprises setting the channel-quality threshold to a valueselected based on a type of communication in which the UE engages,including (i) making a determination of whether the type ofcommunication is uplink-heavy or rather uplink-light, (ii) if thedetermination is that the type of communication is uplink-heavy ratherthan uplink-light, then, based on the determination, selecting as thechannel-quality threshold a first channel-quality threshold rather thana second channel-quality threshold based on the first channel-qualitythreshold being lower than the second channel-quality threshold, and(iii) if the determination is that the type of communication isuplink-light rather than uplink-heavy, then, based on the determination,selecting as the channel-quality threshold the second channel-qualitythreshold rather than the first channel-quality threshold based on thesecond channel-quality threshold being higher than the firstchannel-quality threshold; and wherein the controller is furtherconfigured to apply the dynamically set channel-quality threshold tocontrol when to deconfigure the uplink SCell from service of the UE. 2.The access node of claim 1, wherein the controller comprises aprocessing unit, non-transitory data storage, and program instructionsstored in the non-transitory data storage and executable by theprocessing unit to carry out the dynamically setting and applying. 3.The access node of claim 1, wherein the channel-quality threshold is adownlink channel quality value, wherein applying the dynamically setchannel-quality threshold to control when to deconfigure the uplinkSCell from service of the UE comprises: receiving from the UE, throughthe wireless communication interface, a report of downlink channelquality; making a determination of whether the reported downlink channelquality is at least as low as the dynamically set channel-qualitythreshold; and responsive to the determination being affirmative,deconfiguring the uplink SCell from service of the UE.
 4. The accessnode of claim 3, wherein the downlink channel quality comprises downlinkreference signal receive power (RSRP).
 5. The access node of claim 1,wherein setting the channel-quality threshold to the value selectedbased on the type of communication in which the UE engages comprises:when the access node is operating with the channel-quality threshold setto a default value, making a determination of whether the type ofcommunication is uplink-heavy rather than uplink-light; responsive tothe determination being affirmative, causing the access node totransition from operating with the channel-quality threshold set to thedefault value to operating instead with the channel-quality thresholdset to a value lower than the default value.
 6. The access node of claim5, wherein the controller is further configured to establish the defaultvalue through iterative adjustment of the channel-quality thresholdbased on uplink spectral efficiency of the access node.
 7. The accessnode of claim 1, wherein the setting the channel-quality threshold tothe value selected based on the one or more operational circumstances ofthe UE comprises setting the channel-quality threshold to a valueselected based on both (i) the type of communication in which the UEengages and (ii) a power class of the UE.
 8. Non-transitory data storagestoring instructions executable by a processing unit to cause an accessnode to carry out operations, wherein the access node comprises awireless communication interface including an antenna structure throughwhich to provide wireless service on a plurality of carriers and abackhaul communication interface through which to communicate on a corenetwork, wherein the operations include controlling service of a userequipment device (UE) when the UE is served by the access node withuplink carrier-aggregation over a connection encompassing multipleuplink channels including a primary uplink channel (uplink PCell) and asecondary uplink channel (uplink SCell), wherein the operations furtherinclude dynamically setting a channel-quality threshold applicable tocontrol when to deconfigure the uplink SCell from service of the UE,wherein the dynamically setting the channel-quality threshold comprises:(i) determining a type of communication in which the UE engages,including determining whether the type of communication is uplink-heavyor rather uplink-light, and (ii) using the determined type ofcommunication to set the channel-quality threshold applicable to controlwhen to deconfigure the uplink SCell from service of the UE, including(a) if the determined type of communication is uplink-heavy, thensetting the channel-quality threshold to a first threshold value, and(b) if the determined type of communication is uplink-light, thensetting the channel-quality threshold to a second threshold value higherthan the first threshold value, and wherein the operations furtherinclude applying the dynamically set channel-quality threshold tocontrol when to deconfigure the uplink SCell from service of the UE. 9.The non-transitory data storage of claim 8, wherein the channel-qualitythreshold is a downlink channel quality value, wherein applying thedynamically set channel-quality threshold to control when to deconfigurethe uplink SCell from service of the UE comprises: receiving from theUE, through the wireless communication interface, a report of downlinkchannel quality; making a determination of whether the reported downlinkchannel quality is at least as low as the dynamically setchannel-quality threshold; and responsive to the determination beingaffirmative, deconfiguring the uplink SCell from service of the UE. 10.A method for controlling wireless service of a user equipment device(UE) by an access node, the method comprising: serving, by the accessnode, the UE with uplink carrier-aggregation over a connectionencompassing multiple uplink channels including a primary uplink channel(uplink PCell) and a secondary uplink channel (uplink SCell);dynamically setting, by the access node, a channel-quality thresholdapplicable to control when to deconfigure the uplink SCell from serviceof the UE, wherein dynamically setting the channel-quality thresholdcomprises setting the channel-quality threshold to a value selectedbased on one or more operational circumstances of the UE, whereinsetting the channel-quality threshold to the value selected based on theone or more operational circumstances of the UE comprises setting thechannel-quality threshold to a value selected based on a type ofcommunication in which the UE engages, including (i) making adetermination of whether the type of communication is uplink-heavy orrather uplink-light, (ii) if the determination is that the type ofcommunication is uplink-heavy rather than uplink-light, then, based onthe determination, selecting as the channel-quality threshold a firstchannel-quality threshold rather than a second channel-quality thresholdbased on the first channel-quality threshold being lower than the secondchannel-quality threshold, and (iii) if the determination is that thetype of communication is uplink-light rather than uplink-heavy, then,based on the determination, selecting as the channel-quality thresholdthe second channel-quality threshold rather than the firstchannel-quality threshold based on the second channel-quality thresholdbeing higher than the first channel-quality threshold; and applying, bythe access node, the dynamically set channel-quality threshold tocontrol when to deconfigure the uplink SCell from service of the UE. 11.The method of claim 10, wherein the determination is a firstdetermination, and wherein the channel-quality threshold is a downlinkchannel quality value, wherein applying the dynamically setchannel-quality threshold to control when to deconfigure the uplinkSCell from service of the UE comprises: receiving from the UE a reportof downlink channel quality; making a second determination of whetherthe reported downlink channel quality is at least as low as thedynamically set channel-quality threshold; and responsive to the seconddetermination being affirmative, deconfiguring the uplink SCell fromservice of the UE.
 12. The method of claim 10, wherein setting thechannel-quality threshold to the value selected based on the type ofcommunication in which the UE engages comprises: operating with thechannel-quality threshold set to a default value; and responsive to thedetermination being that the type of communication is uplink-heavyrather than uplink-light, transitioning from operating with thechannel-quality threshold set to the default value to operating insteadwith the channel-quality threshold set to a value lower than the defaultvalue.
 13. The method of claim 10, wherein the setting thechannel-quality threshold to the value selected based on the one or moreoperational circumstances of the UE comprises setting thechannel-quality threshold to a value selected based on both (i) the typeof communication in which the UE engages and (ii) a power class of theUE.
 14. The method of claim 13, wherein the determination is a firstdetermination, and wherein the power class of the UE defines a maximumtransmission power of the UE and is selected from the group consistingof (i) standard-power and (ii) high-power, wherein high-power defines ahigher maximum transmission power than standard-power, and wherein theselecting of the value being additionally based on the power class ofthe UE comprises: making a second determination of whether the powerclass of the UE is standard-power or rather high-power; if the seconddetermination is that the power class of the UE is standard-power ratherthan high-power, then, based additionally on the second determination,setting the channel-quality threshold to a first value rather than asecond value based on the first value being higher than the secondvalue; and if the second determination is that the power class of the UEis high-power rather than standard-power, then, based additionally onthe second determination, setting the channel-quality threshold to thesecond value rather than the first value based on the second value beinglower than the first value.